The Role of Reactive Species on Innate Immunity

Mitigation of cadmium toxicity in African catfish using biological Nano chitosan: insights into biochemical, genotoxic, and histopathological effects

BACKGROUND

Cadmium is a highly toxicant heavy metal that poses serious risks to aquatic organisms, animals, and humans. Recent studies have investigated using biological chitosan nanoparticles (Bio-CHNPs) as a potential solution to alleviate the harmful effects of Cd exposure, particularly in aquaculture. Bio-CHNPs have gained attention for their applications in drug delivery and biomedical research, indicating their potential utility in addressing environmental toxicity.

OBJECTIVE

This research aims to explore the effectiveness of Bio-CHNPs in mitigating cadmium chloride (CdCL2) toxicity in African catfish (Clarias gariepinus).

METHODS

One hundred and twenty (n = 120) catfish were divided into 4 groups; G1 (control); G2, intoxicated with 10% LC50 of CdCL2; G3 received 3 g/kg of Bio-CNPs; G4, treated with 10% LC50 of CdCL2 and Bio-CNPs 3 g/kg feed.

RESULTS

CdCl2 exposure resulted in severe liver, intestine, and kidney damage, which was evidenced by alterations in biochemical parameters, hormonal imbalance, DNA damage, and micronucleus formation. Antioxidant defense mechanisms were compromised, as the activities of Superoxide Dismutase (SOD), Total Antioxidant Capacity (TAC), and Catalase (CAT) were reduced. mRNA expression levels of inflammatory cytokines such as IL-1β, IL-8, and LBP were also significantly elevated following CdCl2 exposure. Conversely, Bio-CHNPs treatment showed antioxidant and anti-inflammatory effects, greatly lowering the biochemical, genotoxic, and histopathological effects induced by CdCl2.

CONCLUSION

The outcomes of this study are indicative of the potential of Bio-CHNPs as a promising aquaculture feed supplement, with a dual advantage of antagonizing the toxicity of environmental pollutants like Cd and imparting antioxidant and immunomodulatory effects. Bio-CHNP supplementation can be a viable strategy for remedying aquatic environmental heavy metal pollution, with the ultimate safeguarding of human health and ecosystem balance.

Exploring Alternate Targets for Respiratory Resuscitation in Patients With Sepsis and Septic Shock

Despite limited evidence to support it, resuscitation in sepsis has primarily targeted aggressive fluid administration and liberal administration of oxygen. In 2024, new thought paradigms emerged to suggest that dysregulation of aerobic metabolism are essential underpinnings of sepsis, and that in fact, aggressive resuscitation with fluids liberal oxygen could potentially aggravate oxidative stress and organ failure in sepsis. As sepsis continues to be shaped and molded by the latest research; therapies targeting sepsis and septic shock management warrant similar scrutiny.

METHODS

We searched literature pertaining to what is known about metabolic dysregulation in sepsis, to consider approaches to identifying new targets for resuscitation and management in sepsis.

RESULTS

Therapeutic hypoxemic targets of 88-92% have been shown to have some benefit in sepsis resuscitation in a limited number of studies. The benefit is believed to result from protection from excessive accumulation of harmful reactive oxygen species.

CONCLUSION

Limited supporting evidence exists in the literature to recommend targeted hypoxemia or hypercapnia in patients with sepsis. Mixed results have been observed in the literature, including minimal benefit to mortality. New research designs with consideration to the dysregulated metabolic sequelae in sepsis could improve the meaningfulness of these therapies in sepsis.

Targeting respiratory virus-induced reactive oxygen species in airways diseases

The immune response to virus infection in the respiratory tract must be carefully balanced to achieve pathogen clearance without excessive immunopathology. For chronic respiratory diseases where there is ongoing inflammation, such as in asthma and COPD, airway immune balance is perturbed, and viral infection frequently worsens (exacerbates) these conditions. Reactive oxygen species (ROS) are critical to the induction and propagation of inflammation, and when appropriately regulated, ROS are vital cell signalling molecules and contribute to innate immunity. However, extended periods of high ROS concentration can cause excessive cellular damage that dysregulates antiviral immunity and promotes inflammation. Traditional antioxidant therapeutics have had limited success treating inflammatory diseases such as viral exacerbations of asthma or COPD, owing to nonspecific pharmacology and poorly understood pharmacokinetic properties. These drawbacks could be addressed with novel drug delivery technologies and pharmacological agents. This review summarises current research on ROS imbalances during virus infection, discusses the commercially available mitochondrial antioxidant drugs that have progressed to clinical trial and assesses novel drug delivery approaches for antioxidant delivery to the airways. Additionally, it provides a perspective on future research into pharmacological targeting of ROS for the treatment of respiratory virus infection and disease.

Free radicals and their impact on health and antioxidant defenses: a review

Free radicals, characterized by the presence of unpaired electrons, are highly reactive species that play a significant role in human health. These molecules can be generated through various endogenous processes, such as mitochondrial respiration and immune cell activation, as well as exogenous sources, including radiation, pollution, and smoking. While free radicals are essential for certain physiological processes, such as cell signaling and immune defense, their overproduction can disrupt the delicate balance between oxidants and antioxidants, leading to oxidative stress. Oxidative stress results in the damage of critical biomolecules like DNA, proteins, and lipids, contributing to the pathogenesis of various diseases. Chronic conditions such as cancer, cardiovascular diseases, neurodegenerative disorders, and inflammatory diseases have been strongly associated with the harmful effects of free radicals. This review provides a comprehensive overview of the characteristics and types of free radicals, their mechanisms of formation, and biological impacts. Additionally, we explore natural compounds and extracts studied for their antioxidant properties, offering potential therapeutic avenues for managing free radical-induced damage. Future research directions are also discussed to advance our understanding and treatment of free radical-associated diseases.

Mechanisms and management of thrombosis in cancer: Focus on gastrointestinal malignancies

Cancer patients have an increased risk of venous thromboembolism, which is their second cause of death after disease progression itself. Several thrombotic risk factors coexist in cancer patients, including the ability of both cancer and tumoral microenvironment's cells to directly or indirectly activate platelets and the enzymes of the coagulation cascade, resulting in a hypercoagulable state of blood. This narrative review gives an overview of the main mechanisms leading to venous thromboembolism in cancer patients, including the role that platelets and the clotting proteins may have in tumor growth and metastasis. Of note, the hemostatic balance is altered in cancer patients who may, next to a thrombosis tendency, also have an increased risk of bleeding. To highlight the complexity and the precariousness of the hemostatic balance of these patients, we discuss 2 specific gastrointestinal malignancies: hepatocellular carcinoma, which is frequently associated with liver cirrhosis, a condition that causes profound alterations of hemostasis, and colorectal cancer, which is characterized by a fragile mucosa that is prone to bleeding. Understanding the molecular mechanisms of cancer-associated thrombosis may give a unique opportunity to develop new innovative drugs, acting differently on distinct pathways and potentially allowing to reduce the risk of bleeding related to antithrombotic therapies. SIGNIFICANCE STATEMENT: The topic is significant because understanding the molecular mechanisms leading to cancer-associated thrombosis and bleeding, focusing on gastrointestinal malignancies, enables the development of more rationale and innovative antithrombotic strategies for cancer-associated thrombosis. Eventually, this will support an improved and patient-tailored antithrombotic management in vulnerable oncologic patients.

Evaluation of oxidative stress biomarkers for differentiating bacterial and viral infections: a comparative study of glutathione disulfide (GSSG) and reduced glutathione (GSH)

Background and aims

This study evaluates the potential of oxidative stress biomarkers, specifically glutathione disulfide (GSSG) and reduced glutathione (GSH), for differentiating bacterial and viral infections. Oxidative stress plays a crucial role in the immune response, and glutathione is a key regulator of cellular redox balance. The aim was to assess whether differences in GSH and GSSG levels could be used as diagnostic markers for infection type.

Methods

A chemiluminescence-based method evaluated GSH and GSSG as potential biomarkers for distinguishing between bacterial and viral infections. The GSH and GSSG concentrations were analyzed across bacterial, viral, and control groups.

Results

Our data revealed significant differences in the GSH/GSSG ratio between the analyzed groups, with bacterial infections showing higher oxidative stress markers compared to viral infections. A combined analysis of GSH and GSSG concentrations, visualized through heatmaps and ROC curves, improved diagnostic accuracy, with clustering patterns distinguishing infection types.

Conclusions

These findings suggest that the GSH/GSSG ratio could be used as a biomarker in distinguishing between bacterial and viral infections, offering potential clinical applications for more accurate diagnosis. Further research is required to validate these results in larger cohorts and to explore the underlying mechanisms of oxidative stress in pathogen-specific immune responses.

Lessons from the field: Trichoderma in agriculture and human health

The use of Trichoderma in agriculture as both a biocontrol agent and biofertilizer hinges on its ability to colonize the rhizosphere, promote plant growth, endure adverse environments, compete for space and nutrients, and produce enzymes and secondary metabolites to mycoparasitize and infect other fungus. In humans, Trichoderma exhibits the capacity to infect various bodily tissues, leading to Trichodermosis. There has been a notable increase in cases ranging from superficial to fatal, invasive, and disseminated infections, particularly among immunocompromised individuals. Trichoderma species employ diverse strategies to colonize and survive in various environments, infecting phytopathogens; however, the mechanisms and virulence factors contributing to human infections remain poorly understood. In this mini review, we provide a brief overview and contextualization of the virulence mechanisms employed by Trichoderma in parasitizing other fungi, as well as those implicated in modulating plant immunity and inducing human infections. Furthermore, we discuss the similarity of these virulence factors capable of modulating the mammalian immune system and their potential implications for human infection.

Hesperetin-7-O-rhamnoglucoside ameliorates dichlorvos-facilitated cardiotoxicity in rats by counteracting ionoregulatory, ion pumps, redox, and lipid homeostasis disruptions

The contamination of edible agricultural goods with pesticides, including dichlorvos (DVDP), poses a substantial public health risk, promoting severe morbidity and mortality, especially in developing countries. It has been shown that hesperidin (hesperetin-7-O-rhamnoglucoside or Hes-7-RGlc) preserves cytomembrane, redox, and lipid homeostasis; unfortunately, its function on dichlorvos-incited heart damage has not been investigated. This work explored the ameliorative influence of Hes-7-RGlc on DVDP-activated cardiotoxicity. For this end, forty-two rats were randomly appropriated into seven groups (6 rats/group): Control, DVDP alone (8 mg.kg⁻¹day⁻¹), DVDP supplied with either Hes-7-RGlc (50 and 100 mg.kg⁻¹day⁻¹) or the reference medication atropine (0.2 mg.kg⁻¹day⁻¹), and Hes-7-RGlc alone (50 and 10 mg.kg⁻¹day⁻¹) were the seven groups investigated. DVDP was administered orally for seven days, followed by fourteen days of Hes-7-RGlc therapy. Then the rats were euthanized, and their blood and hearts were removed. Hes-7-RGlc chemotherapy substantially (p<0.05) restored DVDP-elicited dynamics in plasma and cardiac/myocardium creatine kinase isoenzyme (CK-MB), major lipids (cholesterol, triacylglycerol, and phospholipids), electrolytes (Na⁺, K⁺, Ca²⁺, Mg²⁺, Cl⁻), and total protein. Hes-7-RGlc remedy decidedly (p<0.05) abolished DDVP-stimulated amplification in the cardiac concentration of H₂O₂, NO and malondialdehyde; annulled DVDP-educed decreases in heart GSH levels, activities of GST, SOD, catalase, and glutathione peroxidase, ion transporters (Na⁺/K⁺-ATPase and Ca²⁺/Mg²⁺-ATPase), ALT, AST, ALP, and LDH-1. Collectively, Hes-7-RGlc can be advocated as a natural supplementary candidate and blocker of DVDP-provoked heart deficits via its capacity to reverse disruptions of electrolytes, ion pumps, redox status, and lipid homeostasis.

A glucose-rich heteropolysaccharide from Marsdenia tenacissima (Roxb.) Wight et Arn. and its zinc-modified complex enhance immunoregulation by regulating TLR4-Myd88-NF-κB pathway

A previously unreported immunological polysaccharide (MTP70-1) was obtained from Marsdenia tenacissima (Roxb.) Wight et Arn. MTP70-1 (2738 Da) is a heteropolysaccharide that mainly consists of (1 → 5)-linked-L-Araf, t-D-Glcp, (1 → 3,5)-linked-L-Araf, (1 → 4)-linked-D-Galp, (1 → 6)-linked-D-Glcp, and (1 → 3,6)-linked-D-Manp. In vitro cell assays revealed that MTP70-1 exhibits moderate immunomodulatory effects at the cellular level, and MTP70-1 was further modified with zinc to improve these effects. These modifications enhanced the immunomodulatory effects of MTP70-1, as phagocytosis was enhanced, the secretion of cytokines (TNF-α, IL-6, IL-1β, and IL-18) was increased, and the generation of chemokines (NO and ROS) in macrophages was enhanced. The intracellular mechanism by which MTP70-1 and MTP70-Zn activate macrophages was further revealed to be closely related to the TLR4-Myd88-NF-κB signaling pathway. In addition, a microscale thermophoresis binding (MST) assay confirmed that Zn modification can effectively enhance the binding affinity of MTP70-1 for TLR4. Ultimately, better immune-enhancing activity was attained with MTP70-Zn than MTP70-1. The immune-enhancing activity of MTP70-Zn was further demonstrated through zebrafish assays, which revealed that MTP70-Zn can effectively enhance the proliferation of macrophages and neutrophils.

Beta-hemolytic Streptococci in respiratory illness

Beta-hemolytic Streptococci are associated with various respiratory illnesses, such as pharyngitis, scarlet fever and pneumonia, highlighting the need for enhanced diagnostic, therapeutic and preventive strategies. Advances in immunology and molecular biology have provided insights into the etiology and host immune responses to these infections, but many questions remain unanswered. Further research is needed to develop advanced diagnostics, explore vaccine candidates, understand immune responses and address antibiotic resistance. Epidemiological studies are crucial to improving our understanding of these infections and their public health impact. A multidisciplinary approach integrating epidemiology, microbiology, immunology and clinical medicine is essential to reduce the burden of beta-hemolytic streptococcal infections and improve overall treatment and prevention efforts.

Post-translational modifications of fibrinogen: implications for clotting, fibrin structure and degradation

Fibrinogen, a blood plasma protein with a key role in hemostasis and thrombosis, is highly susceptible to post-translational modifications (PTMs), that significantly influence clot formation, structure, and stability. These PTMs, which include acetylation, amidation, carbamylation, citrullination, dichlorination, glycation, glycosylation, guanidinylation, hydroxylation, homocysteinylation, malonylation, methylation, nitration, oxidation, phosphorylation and sulphation, can alter fibrinogen biochemical properties and affect its functional behavior in coagulation and fibrinolysis. Oxidation and nitration are notably associated with oxidative stress, impacting fibrin fiber formation and promoting the development of more compact and resistant fibrin networks. Glycosylation and glycation contribute to altered fibrinogen structural properties, often resulting in changes in fibrin clot density and susceptibility to lysis, particularly in metabolic disorders like diabetes. Acetylation and phosphorylation, influenced by medications such as aspirin, modulate clot architecture by affecting fiber thickness and clot permeability. Citrullination and homocysteinylation, although less studied, are linked to autoimmune conditions and cardiovascular diseases, respectively, affecting fibrin formation and stability. Understanding these modifications provides insights into the pathophysiology of thrombotic disorders and highlights potential therapeutic targets. This review comprehensively examines the current literature on fibrinogen PTMs, their specific sites, biochemical pathways, and their consequences on fibrin clot architecture, clot formation and clot lysis.

Dietary Antioxidants and Natural Compounds in Preventing Thrombosis and Cardiovascular Disease

Reactive oxygen species (ROS) contribute to endothelial dysfunction, platelet activation, and coagulation abnormalities, promoting thrombus formation. Given the growing interest in non-pharmacological approaches to modulate oxidative stress, we examine the potential of various dietary interventions and antioxidant supplementation in reducing oxidative damage and preventing thrombotic events. Key dietary patterns, such as the Mediterranean, Dietary Approaches to Stop Hypertension (DASH), and ketogenic diets, as well as antioxidant-rich supplements like curcumin, selenium, and polyphenols, demonstrate promising effects in improving oxidative stress markers, lipid profiles, and inflammatory responses. This review highlights recent advances in the field, drawing from in vitro, ex vivo, and clinical studies, and underscores the importance of integrating dietary strategies into preventive and therapeutic approaches for managing thrombosis and cardiovascular health. Further research is needed to better understand long-term effects and personalize these interventions for optimizing patient outcomes.

How Do ROS Induce NETosis? Oxidative DNA Damage, DNA Repair, and Chromatin Decondensation

Neutrophil extracellular traps (NETs) are intricate, DNA-based, web-like structures adorned with cytotoxic proteins. They play a crucial role in antimicrobial defense but are also implicated in autoimmune diseases and tissue injury. The process of NET formation, known as NETosis, is a regulated cell death mechanism that involves the release of these structures and is unique to neutrophils. NETosis is heavily dependent on the production of reactive oxygen species (ROS), which can be generated either through NADPH oxidase (NOX) or mitochondrial pathways, leading to NOX-dependent or NOX-independent NETosis, respectively. Recent research has revealed an intricate interplay between ROS production, DNA repair, and NET formation in different contexts. UV radiation can trigger a combined process of NETosis and apoptosis, known as apoNETosis, driven by mitochondrial ROS and DNA repair. Similarly, in calcium ionophore-induced NETosis, both ROS and DNA repair are key components, but only play a partial role. In the case of bacterial infections, the early stages of DNA repair are pivotal. Interestingly, in serum-free conditions, spontaneous NETosis occurs through NOX-derived ROS, with early-stage DNA repair inhibition halting the process, while late-stage inhibition increases it. The intricate balance between DNA repair processes and ROS production appears to be a critical factor in regulating NET formation, with different pathways being activated depending on the nature of the stimulus. These findings not only deepen our understanding of the mechanisms behind NETosis but also suggest potential therapeutic targets for conditions where NETs contribute to disease pathology.

Role and Function of Peroxisomes in Neuroinflammation

Peroxisomes are organelles involved in many cellular metabolic functions, including the degradation of very-long-chain fatty acids (VLCFAs; C ≥ 22), the initiation of ether-phospholipid synthesis, and the metabolism of reactive oxygen species. All of these processes are essential for the maintenance of cellular lipid and redox homeostasis, and their perturbation can trigger inflammatory response in immune cells, including in the central nervous system (CNS) resident microglia and astrocytes. Consistently, peroxisomal disorders, a group of congenital diseases caused by a block in peroxisomal biogenesis or the impairment of one of the peroxisomal enzymes, are associated with neuroinflammation. Peroxisomal function is also dysregulated in many neurodegenerative diseases and during brain aging, both of which are associated with neuroinflammation. This suggests that deciphering the role of peroxisomes in neuroinflammation may be important for understanding both congenital and age-related brain dysfunction. In this review, we discuss the current advances in understanding the role and function of peroxisomes in neuroinflammation.

Salivary assessment of the immune/inflammatory responses and oxidative stress in older adults vaccinated with CoronaVac or ChadOx-1

BACKGROUND

Although important information concerning COVID-19 vaccination is available, the effects of the CoronaVac and ChadOx-1 vaccines on immunity and the redox balance in the upper airway mucosa of the aged population are not fully understood. Therefore, the aim of this study was to investigate the impacts of two doses of the CoronaVac or ChadOx-1 vaccine on immune/inflammatory responses and oxidative stress in the airway mucosa of older adults.

METHODS

Seventy-six older adults of both sexes, with a mean age of 75.1 ± 6.4 years, were separated according to vaccination status into the CoronaVac (n = 52) and ChadOx-1 (n = 24) groups. Saliva samples were collected before (pre) and 30 days after (post) the administration of the second dose of the CoronaVac or ChadOx-1 vaccine to assess the levels of antibodies (sIgA and IgG), antimicrobial peptides, cytokines, and oxidant/antioxidant agents.

RESULTS

The immunogenicity in the ChadOx-1 group was 37.5% for sIgA and 25% for IgG, while that in the CoronaVac group was 18.9% for sIgA and 13.2% for IgG. Intergroup analysis revealed that (1) lower levels of IFN-α, IFN-γ, and IL-10 and a greater IFN-γ/IL-10 ratio, in addition to a greater IL-6/IL-10 ratio, were found in both the pre- and postvaccination periods, and (2) lower levels of total sIgA, IL-12p70, IL-17A, TNF-α, and the IL-12p70/IL-10 ratio, in addition to higher levels of specific sIgA for SARS-CoV-2 antigens and lysozyme, were observed only in the postvaccination period in the ChadOx-1 group than in the CoronaVac group. Intragroup analysis revealed (1) a significant increase in the salivary levels of total peroxides in the postvaccination period compared to those in the prevaccination period in both volunteer groups; (2) a decrease in the levels of lysozyme and the ratio between total antioxidant capacity (TAC) and total peroxides in the postvaccination period in the CoronaVac group compared with those in the prevaccination period; and (3) decreases in the TNF-α, IL-6, and IL-12p70 levels, and the IL-12p70/IL-10 ratio in the ChadoX-1 group, as well as a higher lactoferrin concentration in the postvaccination period than in the prevaccination period. Several positive and negative correlations between the parameters assessed here were found.

CONCLUSIONS

In general, the ChadOx-1 group exhibited improvements in both immune/inflammatory responses and redox balance and greater immunogenicity than did the CoronaVac group.

Sulfate-Reducing Bacteria Induce Pro-Inflammatory TNF-α and iNOS via PI3K/Akt Pathway in a TLR 2-Dependent Manner

Desulfovibrio, resident gut sulfate-reducing bacteria (SRB), are found to overgrow in diseases such as inflammatory bowel disease and Parkinson's disease. They activate a pro-inflammatory response, suggesting that Desulfovibrio may play a causal role in inflammation. Class I phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway regulates key events in the inflammatory response to infection. Dysfunctional PI3K/Akt signaling is linked to numerous diseases. Bacterial-induced PI3K/Akt pathway may be activated downstream of toll-like receptor (TLR) signaling. Here, we tested the hypothesis that Desulfovibrio vulgaris (DSV) may induce tumor necrosis factor alpha (TNF-α) and inducible nitric oxide synthase (iNOS) expression via PI3K/Akt in a TLR 2-dependent manner. RAW 264.7 macrophages were infected with DSV, and protein expression of p-Akt, p-p70S6K, p-NF-κB, p-IkB, TNF-α, and iNOS was measured. We found that DSV induced these proteins in a time-dependent manner. Heat-killed and live DSV, but not bacterial culture supernatant or a probiotic Lactobacillus plantarum, significantly caused PI3K/AKT/TNF/iNOS activation. LY294002, a PI3K/Akt signaling inhibitor, and TL2-C29, a TLR 2 antagonist, inhibited DSV-induced PI3K/AKT pathway. Thus, DSV induces pro-inflammatory TNF-α and iNOS via PI3K/Akt pathway in a TLR 2-dependent manner. Taken together, our study identifies a novel mechanism by which SRB such as Desulfovibrio may trigger inflammation in diseases associated with SRB overgrowth.

Inflammasome activity regulation by PUFA metabolites

Oxidative stress and the accompanying chronic inflammation constitute an important metabolic problem that may lead to pathology, especially when the body is exposed to physicochemical and biological factors, including UV radiation, pathogens, drugs, as well as endogenous metabolic disorders. The cellular response is associated, among others, with changes in lipid metabolism, mainly due to the oxidation and the action of lipolytic enzymes. Products of oxidative fragmentation/cyclization of polyunsaturated fatty acids (PUFAs) [4-HNE, MDA, 8-isoprostanes, neuroprostanes] and eicosanoids generated as a result of the enzymatic metabolism of PUFAs significantly modify cellular metabolism, including inflammation and the functioning of the immune system by interfering with intracellular molecular signaling. The key regulators of inflammation, the effectiveness of which can be regulated by interacting with the products of lipid metabolism under oxidative stress, are inflammasome complexes. An example is both negative or positive regulation of NLRP3 inflammasome activity by 4-HNE depending on the severity of oxidative stress. 4-HNE modifies NLRP3 activity by both direct interaction with NLRP3 and alteration of NF-κB signaling. Furthermore, prostaglandin E2 is known to be positively correlated with both NLRP3 and NLRC4 activity, while its potential interference with AIM2 or NLRP1 activity is unproven. Therefore, the influence of PUFA metabolites on the activity of well-characterized inflammasome complexes is reviewed.

A scaffold vaccine to promote tumor antigen cross-presentation via sustained toll-like receptor-2 (TLR2) activation

Cancer vaccination holds great promise for cancer treatment, but its effectiveness is hindered by suboptimal activation of CD8+ cytotoxic T lymphocytes, which are potent effectors to mediate anti-tumor immune responses. A possible solution is to switch antigen-presenting cells to present tumor antigens via the major histocompatibility complex class I (MHC-I) to CD8+ T cells - a process known as cross-presentation. To achieve this goal, we develop a three-dimensional (3D) scaffold vaccine to promote antigen cross-presentation by persisted toll-like receptor-2 (TLR2) activation after one injection. This vaccine comprises polysaccharide frameworks that "hook" TLR2 agonist (acGM) via tunable hydrophobic interactions and forms a 3D macroporous scaffold via click chemistry upon subcutaneous injection. Its retention-and-release of acGM enables sustained TLR2 activation in abundantly recruited dendritic cells in situ, inducing intracellular production of reactive oxygen species (ROS) in optimal kinetics that crucially promotes efficient antigen cross-presentation. The scaffold loaded with model antigen ovalbumin (OVA) or tumor specific antigen can generate potent immune responses against lung metastasis in B16-OVA-innoculated wild-type mice or spontaneous colorectal cancer in transgenic ApcMin/+ mice, respectively. Notably, it requires neither additional adjuvants nor external stimulation to function and can be adjusted to accommodate different antigens. The developed scaffold vaccine may represent a new, competent tool for next-generation personalized cancer vaccination.

Immunostimulatory Effect of Ovomucin Hydrolysates by Pancreatin in RAW 264.7 Macrophages via Mitogen-Activated Protein Kinase (MAPK) Signaling Pathway

Ovomucin (OM), which has insoluble fractions is a viscous glycoprotein, found in egg albumin. Enzymatic hydrolysates of OM have water solubility and bioactive properties. This study investigated that the immunostimulatory effects of OM hydrolysates (OMHs) obtained by using various proteolytic enzymes (Alcalase®, bromelain, α-chymotrypsin, Neutrase®, pancreatin, papain, Protamax®, and trypsin) in RAW 264.7 cells. The results showed that OMH prepared with pancreatin (OMPA) produced the highest levels of nitrite oxide in RAW 264.7 cells, through upregulation of inducible nitric oxide synthase mRNA expression. The production of pro-inflammatory cytokines such as tumor necrosis factor-α and interleukin-6 were increased with the cytokines mRNA expression. The effect of OMPA on mitogen-activated protein kinase signaling pathway was increased the phosphorylation of p38, c-Jun NH2-terminal kinase, and extracellular signal-regulated kinase in a concentration-dependent manner. Therefore, OMPA could be used as a potential immune-stimulating agent in the functional food industry.

Probiotic bacteria can modulate immune responses to paratuberculosis vaccination

Mycobacterium avium subsp. paratuberculosis (Map) is the etiological agent of paratuberculosis (PTB), a chronic intestinal inflammatory disease that causes high economical losses in dairy livestock worldwide. Due to the absence of widely available preventive or therapeutical treatments, new alternative therapies are needed. In this study, the effect of a probiotic alone or in combination with a commercial vaccine has been evaluated in a rabbit model. Vaccination enhanced the humoral response, exerted a training effect of peripheral polymorphonuclear neutrophils (PMNs) against homologous and heterologous stimuli, stimulated the release of pro-inflammatory cytokines by gut-associated lymphoid tissue (GALT) macrophages, and reduced the bacterial burden in GALT as well. However, the administration of the probiotic after vaccination did not affect the PMN activity, increased metabolic demand, and supressed pro-inflammatory cytokines, although humoral response and bacterial burden decrease in GALT was maintained similar to vaccination alone. The administration of the probiotic alone did not enhance the humoral response or PMN activity, and the bacterial burden in GALT was further increased compared to the only challenged group. In conclusion, the probiotic was able to modulate the immune response hampering the clearance of the infection and was also able to affect the response of innate immune cells after vaccination. This study shows that the administration of a probiotic can modulate the immune response pathways triggered by vaccination and/or infection and even exacerbate the outcome of the disease, bringing forward the importance of verifying treatment combinations in the context of each particular infectious agent.

Peroxynitrite: a multifaceted oxidizing and nitrating metabolite

Peroxynitrite, a short-lived and reactive oxidant, emerges from the diffusion-controlled reaction between the superoxide radical and nitric oxide. Evidence shows that peroxynitrite is a critical mediator in physiological and pathological processes such as the immune response, inflammation, cancer, neurodegeneration, vascular dysfunction, and aging. The biochemistry of peroxynitrite is multifaceted, involving one- or two-electron oxidations and nitration reactions. This minireview highlights recent findings of peroxynitrite acting as a metabolic mediator in processes ranging from oxidative killing to redox signaling. Selected examples of nitrated proteins (i.e., 3-nitrotyrosine) are surveyed to underscore the role of this post-translational modification on cell homeostasis. While accumulated evidence shows that large amounts of peroxynitrite participates of broad oxidation and nitration events in invading pathogens and host tissues, a closer look supports that low to moderate levels selectively trigger signal transduction cascades. Peroxynitrite probes and redox-based pharmacology are instrumental to further understand the biological actions of this reactive metabolite.

Advanced Dressings for Chronic Wound Management

Wound healing, particularly for chronic wounds, presents a considerable difficulty due to differences in biochemical and cellular processes that occur in different types of wounds. Recent technological breakthroughs have notably advanced the understanding of diagnostic and therapeutic approaches to wound healing. The evolution in wound care has seen a transition from traditional textile dressings to a variety of advanced alternatives, including self-healing hydrogels, hydrofibers, foams, hydrocolloids, environment responsive dressings, growth factor-based therapy, bioengineered skin substitutes, and stem cell and gene therapy. Technological advancements, such as 3D printing and electronic skin (e-skin) therapy, contribute to the customization of wound healing. Despite these advancements, effectively managing chronic wounds remains challenging. This necessitates the development of treatments that consider performance, risk-benefit balance, and cost-effectiveness. This review discusses innovative strategies for the healing of chronic wounds. Incorporating biomarkers into advanced dressings, coupled with corresponding biosensors and drug delivery formulations, enables the theranostic approach to the treatment of chronic wounds. Furthermore, integrating advanced dressings with power sources and user interfaces like near-field communication, radio frequency identification, and Bluetooth enhances real-time monitoring and on-demand drug delivery. It also provides a thorough evaluation of the advantages, patient compliance, costs, and durability of advanced dressings, emphasizing smart formulations and their preparation methods.

Assessment of In Vitro Antioxidant and Anti-Inflammatory Activities of Pumpkin (Cucurbita pepo) Natural Plant

Objectives

The objective of this research was to investigate the potential anti-inflammatory properties of the Cucurbita pepo fruit. Given the adverse effects associated with long-term use or excessive doses of conventional anti-inflammatory medications, exploring herbal therapies as alternatives has become increasingly important.

Methods

Various preliminary tests and antioxidant assays, both enzymatic and non-enzymatic, were conducted on the C . pepo fruit. Bioactive substances present in the fruit, including alkaloids, carbohydrates, flavonoids, tannins, amino acids, triterpenoids, and saponin glycosides, were identified through early analysis. Different extraction solvents, such as chloroform, methanol, and water, were utilized to extract samples. The methanolic extract was subjected to further testing for its in vitro anti-inflammatory characteristics. This involved evaluating their ability to stabilize RBC membranes, inhibit protein denaturation, and suppress proteinase activity using two concentrations (150 µg/ml and 300 µg/ml) of the extract.

Results

The methanolic extract of the C. pepo fruit exhibited strong free radical scavenging activity in both DPPH and H2O2 assays. Moreover, it demonstrated the dose-dependent stabilization of RBC membranes, resulting in reduced hemolysis, protein denaturation, and proteinase activity. These findings suggest potent anti-inflammatory effects of the methanolic extract.

Conclusion

This research study has found that the C. pepo fruit methanolic extract significantly reduced inflammation. This demonstrates the promise of natural chemicals as less risky substitutes for traditional anti-inflammatory medications. Potentially safe and efficient treatments for inflammatory illnesses could be found in herbal remedies such as the C. pepo fruit. Therefore, this study highlights the significance of exploring herbal remedies as a potential treatment option for inflammation-related diseases.

Can iron chelators ameliorate viral infections?

The redox reactivity of iron is a double-edged sword for cell functions, being either essential or harmful depending on metal concentration and location. Deregulation of iron homeostasis is associated with several clinical conditions, including viral infections. Clinical studies as well as in silico, in vitro and in vivo models show direct effects of several viruses on iron levels. There is support for the strategy of iron chelation as an alternative therapy to inhibit infection and/or viral replication, on the rationale that iron is required for the synthesis of some viral proteins and genes. In addition, abnormal iron levels can affect signaling immune response. However, other studies report different effects of viral infections on iron homeostasis, depending on the class and genotype of the virus, therefore making it difficult to predict whether iron chelation would have any benefit. This review brings general aspects of the relationship between iron homeostasis and the nonspecific immune response to viral infections, along with its relevance to the progress or inhibition of the inflammatory process, in order to elucidate situations in which the use of iron chelators could be efficient as antivirals.

Tissue cytokines in chickens from lines selected for high or low humoral antibody responses, given supplemental Limosilactobacillus reuteri and challenged with Histomonas meleagridis

Histomonas meleagridis, a protozoan parasite, induces blackhead disease (histomoniasis) in poultry. During hatching, chicks from lines divergently selected for high (HAS) and low (LAS) antibody responses to sheep red blood cells were divided into two groups, each of HAS and LAS, and placed in pens with wood shavings as litter. Feed and water were allowed ad libitum. Half of the chicks from each line had Limosilactobacillus reuteri (L. reuteri) inoculated to their drinking water. On day 18, all chicks were given a transcloacal inoculation of 100,000 H. meleagridis cells. Then, 10 days later, they were euthanized, followed by collection of tissues from the brain, cecal tonsil, ceca, liver, thymus, and spleen for qPCR analyses of cytokines involved in immunological development. Changes in cytokine expressions were most numerous in the cecal tonsil, ceca, and liver. In the absence of a functional medication for control of histomoniasis, L. reuteri and/or its secretory product, reuterin, might serve, in some genetic populations, as a means to reduce the impact of histomoniasis in chickens. The data demonstrate that L. reuteri treatment had tissue specificity between the two genetic lines, in which the effects were targeted primarily toward the cecal tonsil, ceca, and liver, which are the primary tissue targets of the parasite (H. meleagridis), as well as the thymus and spleen. However, interactions among main effects reflect that responses to inflammatory markers observed in tissues for one genetic line may not be observed in another.

Understanding mechanisms of antioxidant action in health and disease

Several different reactive oxygen species (ROS) are generated in vivo. They have roles in the development of certain human diseases whilst also performing physiological functions. ROS are counterbalanced by an antioxidant defence network, which functions to modulate ROS levels to allow their physiological roles whilst minimizing the oxidative damage they cause that can contribute to disease development. This Review describes the mechanisms of action of antioxidants synthesized in vivo, antioxidants derived from the human diet and synthetic antioxidants developed as therapeutic agents, with a focus on the gaps in our current knowledge and the approaches needed to close them. The Review also explores the reasons behind the successes and failures of antioxidants in treating or preventing human disease. Antioxidants may have special roles in the gastrointestinal tract, and many lifestyle features known to promote health (especially diet, exercise and the control of blood glucose and cholesterol levels) may be acting, at least in part, by antioxidant mechanisms. Certain reactive sulfur species may be important antioxidants but more accurate determinations of their concentrations in vivo are needed to help assess their contributions.

Bacterial synergies and antagonisms affecting Pseudomonas aeruginosa virulence in the human lung, skin and intestine

Pseudomonas aeruginosa requires a significant breach in the host defense to cause an infection. While its virulence factors are well studied, its tropism cannot be explained only by studying its interaction with the host. Why are P. aeruginosa infections so rare in the intestine compared with the lung and skin? There is not enough evidence to claim specificity in virulence factors deployed by P. aeruginosa in each anatomical site, and host physiology differences between the lung and the intestine cannot easily explain the observed differences in virulence. This perspective highlights a relatively overlooked parameter in P. aeruginosa virulence, namely, potential synergies with bacteria found in the human skin and lung, as well as antagonisms with bacteria of the human intestine.

Potential role of inflammaging mediated by the complement system in enlarged facial pores

BACKGROUND

Enlarged facial pores are a common cosmetic concern of the skin, rather than a disease, and have not received much attention from dermatologists in recent years. Consequently, progress in understanding their pathogenesis has been limited, and current cosmetic solutions have limitations. Given that the complement system has regained interest as a key player in chronic inflammatory skin conditions, various mechanisms involving this system are being investigated.

OBJECTIVE

We aimed to shed light on the mechanism underlying enlarged facial pores by examining the role of the complement system in skin.

METHODS

We conducted a comprehensive literature search utilizing various academic databases including PubMed, Web of Science, and Google Scholar. Employing keywords such as "complement system," "inflammation," "facial pores," "enlarged," and "mechanisms," we compiled a selection of relevant studies. These studies provided a comprehensive understanding of the intricate mechanisms underlying the relationship between the "complement system" and "inflammation" within the context of facial pore enlargement.

RESULTS

Our findings suggest that inflammaging mediated by complement activation may be a critical player in the formation of enlarged facial pores. Specifically, overactivation of the complement system leading to the accumulation of complement fragments could be a major contributor to this process. Notably, the complement system in skin may be involved in a range of skin issues, including aging.

CONCLUSION

Modulating the complement system presents a promising avenue for future research in improving skin health. Further basic and clinical research is necessary to validate these findings, but we hope that this study can serve as a theoretical foundation for the development of targeted cosmetics.

Medicinal Herbs: Promising Immunomodulators for the Treatment of Infectious Diseases

Humans are constantly at high risk of emerging pandemics caused by viral and bacterial infections. The emergence of new pandemics is mainly caused by evolved viruses and bacteria that are highly resistant to existing medications. The rapid evolution of infectious agents demands the urgent investigation of new therapeutic strategies to prevent and treat these infections at an early stage. One of these therapeutic strategies includes the use of medicinal herbs for their antibacterial and antiviral properties. The use of herbal medicines as remedies is very ancient and has been employed for centuries. Many studies have confirmed the antimicrobial activities of herbs against various pathogens in vitro and in vivo. The therapeutic effect of medicinal herbs is mainly attributed to the natural bioactive molecules present in these plants such as alkaloids, flavonoids, and terpenoids. Different mechanisms have been proposed for how medicinal herbs enhance the immune system and combat pathogens. Such mechanisms include the disruption of bacterial cell membranes, suppression of protein synthesis, and limitation of pathogen replication through the inhibition of nucleic acid synthesis. Medicinal herbs have been shown to treat a number of infectious diseases by modulating the immune system's components. For instance, many medicinal herbs alleviate inflammation by reducing pro-inflammatory cytokines (e.g., tumor necrosis factor-alpha (TNF-α), interleukin-1, IL-6) while promoting the production of anti-inflammatory cytokines (e.g., IL-10). Medicinal herbs also play a role in defense against viral and intracellular infections by enhancing the proliferation and functions of natural killer cells, T-helper-1 cells, and macrophages. In this review, we will explore the use of the most common herbs in preventing and treating infectious and non-infectious diseases. Using current and recently published studies, we focus on the immunomodulatory and therapeutic effects induced by medicinal herbs to enhance immune responses during diseases.

From reactive species to disease development: Effect of oxidants and antioxidants on the cellular biomarkers

The influence of modern lifestyle, diet, exposure to chemicals such as phytosanitary substances, together with sedentary lifestyles and lack of exercise play an important role in inducing reactive stress (RS) and disease. The imbalance in the production and scavenging of free radicals and the induction of RS (oxidative, nitrosative, and halogenative) plays an essential role in the etiology of various chronic pathologies, such as cardiovascular diseases, diabetes, neurodegenerative diseases, and cancer. The implication of free radicals and reactive species injury in metabolic disturbances and the onset of many diseases have been accumulating for several decades, and are now accepted as a major cause of many chronic diseases. Exposure to elevated levels of free radicals can cause molecular structural impact on proteins, lipids, and DNA, as well as functional alteration of enzyme homeostasis, leading to aberrations in gene expression. Endogenous depletion of antioxidant enzymes can be mitigated using exogenous antioxidants. The current interest in the use of exogenous antioxidants as adjunctive agents for the treatment of human diseases allows a better understanding of these diseases, facilitating the development of new therapeutic agents with antioxidant activity to improve the treatment of various diseases. Here we examine the role that RS play in the initiation of disease and in the reactivity of free radicals and RS in organic and inorganic cellular components.

Association between Plasmodium Infection and Nitric Oxide Levels: A Systematic Review and Meta-Analysis

Nitric oxide (NO) has been implicated in the pathology of malaria. This systematic review and meta-analysis describe the association between NO levels and malaria. Embase, Ovid, PubMed, Scopus, and Google Scholar were searched to identify studies evaluating NO levels in malaria patients and uninfected controls. Meta-regression and subgroup analyses were conducted to discern differences in NO levels between the groups. Of the 4517 records identified, 21 studies were included in the systematic review and meta-analysis. The findings illustrated significant disparities in NO levels based on geographic location and study time frames. Despite the fluctuations, such as higher NO levels in adults compared to children, no significant differences in mean NO levels between patients and uninfected controls (p = 0.25, Hedge's g: 0.35, 95% confidence interval (CI): -0.25-0.96, I2: 97.39%) or between severe and non-severe malaria cases (p = 0.09, Hedge's g: 0.71, 95% CI: -0.11-1.54, I2: 96.07%) were detected. The systematic review and meta-analysis highlighted inconsistencies in NO levels in malaria patients. Given the high heterogeneity of the results, further studies using standardized metrics for NO measurements and focusing on biochemical pathways dictating NO responses in malaria are imperative to understand the association between NO and malaria.

Chemical Insights into Oxidative and Nitrative Modifications of DNA

This review focuses on DNA damage caused by a variety of oxidizing, alkylating, and nitrating species, and it may play an important role in the pathophysiology of inflammation, cancer, and degenerative diseases. Infection and chronic inflammation have been recognized as important factors in carcinogenesis. Under inflammatory conditions, reactive oxygen species (ROS) and reactive nitrogen species (RNS) are generated from inflammatory and epithelial cells, and result in the formation of oxidative and nitrative DNA lesions, such as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-nitroguanine. Cellular DNA is continuously exposed to a very high level of genotoxic stress caused by physical, chemical, and biological agents, with an estimated 10,000 modifications occurring every hour in the genetic material of each of our cells. This review highlights recent developments in the chemical biology and toxicology of 2'-deoxyribose oxidation products in DNA.

Genetic Modulation of HPV Infection and Cervical Lesions: Role of Oxidative Stress-Related Genes

Human papillomavirus (HPV) infection is a necessary but not sufficient factor for the development of invasive cervical cancer (ICC) and high-grade intraepithelial lesion (HSIL). Oxidative stress is known to play a crucial role in HPV infection and carcinogenesis. In this study, we comprehensively investigate the modulation of HPV infection, HSIL and ICC, and ICC through an exploration of oxidative stress-related genes: CβS, MTHFR, NOS3, ACE1, CYBA, HAP, ACP1, GSTT1, GSTM1, and CYP1A1. Notably, the ACE1 gene emerges as a prominent factor with the presence of the I allele offering protection against HPV infection. The association of NOS3 with HPV infection is perceived with the 4a allele showing a protective effect. The presence of the GSTT1 null mutant correlates with increased susceptibility to HPV infection, HSIL and ICC, and ICC. This study also uncovers intriguing epistatic interactions among some of the genes that further accentuate their roles in disease modulation. Indeed, the epistatic interactions between the BB genotype (ACP1) and DD genotype (ECA1) were shown to increase the risk of HPV infection, and the interaction between BB (ACP1) and 0.0 (GSTT1) was associated with HPV infection and cervical lesions. These findings underscore the pivotal role of four oxidative stress-related genes in HPV-associated cervical lesions and cancer development, enriching our clinical understanding of the genetic influences on disease manifestation. The awareness of these genetic variations holds potential clinical implications.

In vitro activity of hypochlorous acid generating electrochemical bandage against monospecies and dual-species bacterial biofilms

AIMS

As antimicrobial resistance is on the rise, treating chronic wound infections is becoming more complex. The presence of biofilms in wound beds contributes to this challenge. Here, the activity of a novel hypochlorous acid (HOCl) producing electrochemical bandage (e-bandage) against monospecies and dual-species bacterial biofilms formed by bacteria commonly found in wound infections was assessed.

METHODS AND RESULTS

The system was controlled by a wearable potentiostat powered by a 3V lithium-ion battery and maintaining a constant voltage of + 1.5V Ag/AgCl, allowing continuous generation of HOCl. A total of 19 monospecies and 10 dual-species bacterial biofilms grown on polycarbonate membranes placed on tryptic soy agar (TSA) plates were used as wound biofilm models, with HOCl producing e-bandages placed over the biofilms. Viable cell counts were quantified after e-bandages were continuously polarized for 2, 4, 6, and 12 hours. Time-dependent reductions in colony forming units (CFUs) were observed for all studied isolates. After 12 hours, average CFU reductions of 7.75 ± 1.37 and 7.74 ± 0.60 log10 CFU/cm2 were observed for monospecies and dual-species biofilms, respectively.

CONCLUSIONS

HOCl producing e-bandages reduce viable cell counts of in vitro monospecies and dual-species bacterial biofilms in a time-dependent manner in vitro. After 12 hours, >99.999% reduction in cell viability was observed for both monospecies and dual-species biofilms.

The role of antifreeze genes in the tolerance of cold stress in the Nile tilapia (Oreochromis niloticus)

BACKGROUND

Tilapia is one of the most essential farmed fishes in the world. It is a tropical and subtropical freshwater fish well adapted to warm water but sensitive to cold weather. Extreme cold weather could cause severe stress and mass mortalities in tilapia. The present study was carried out to investigate the effects of cold stress on the up-regulation of antifreeze protein (AFP) genes in Nile tilapia (Oreochromis niloticus). Two treatment groups of fish were investigated (5 replicates of 15 fish for each group in fibreglass tanks/70 L each): 1) a control group; the fish were acclimated to lab conditions for two weeks and the water temperature was maintained at 25 °C during the whole experimental period with feeding on a commercial diet (30% crude protein). 2) Cold stress group; the same conditions as the control group except for the temperature. Initially, the temperature was decreased by one degree every 12 h. The fish started showing death symptoms when the water temperature reached 6-8 °C. In this stage the tissue (muscle) samples were taken from both groups. The immune response of fish exposed to cold stress was detected and characterized using Differential Display-PCR (DD-PCR).

RESULTS

The results indicated that nine different up-regulation genes were detected in the cold-stressed fish compared to the control group. These genes are Integrin-alpha-2 (ITGA-2), Gap junction gamma-1 protein-like (GJC1), WD repeat-containing protein 59 isoform X2 (WDRP59), NUAK family SNF1-like kinase, G-protein coupled receptor-176 (GPR-176), Actin cytoskeleton-regulatory complex protein pan1-like (PAN-1), Whirlin protein (WHRN), Suppressor of tumorigenicity 7 protein isoform X2 (ST7P) and ATP-binding cassette sub-family A member 1-like isoform X2 (ABCA1). The antifreeze gene type-II amplification using a specific PCR product of 600 bp, followed by cloning and sequencing analysis revealed that the identified gene is antifreeze type-II, with similarity ranging from 70 to 95%. The in-vitro transcribed gene induced an antifreeze protein with a molecular size of 22 kDa. The antifreeze gene, ITGA-2 and the WD repeat protein belong to the lectin family (sugar-protein).

CONCLUSIONS

In conclusion, under cold stress, Nile tilapia express many defence genes, an antifreeze gene consisting of one open reading frame of approximately 0.6 kbp.

Quinic acid ameliorates ulcerative colitis in rats, through the inhibition of two TLR4-NF-κB and NF-κB-INOS-NO signaling pathways

OBJECTIVE

In this study, the therapeutic effect of quinic acid (QA), which has anti-inflammatory activity, was investigated on acetic acid-induced colitis in male Wistar rats.

METHODS

Ulcerative colitis (UC) was induced in rats by acetic acid intrarectally, and the protective effects of QA in 10, 30, 60, and 100 mg/kg doses were investigated. Rats were treated for 5 days and their colon tissues were dissected out at the end. Macroscopic and histopathological examinations were performed in colon tissues. Also, the expression of inflammatory and apoptotic genes, including TLR4, IL-1β, INOS, IL-6, TNF-α, NF-κB, Caspase-3, Caspase-8, Bax, and Bcl-2, was measured. Biochemistry indices, such as malondialdehyde (MDA) and nitrite oxide (NO) content, in addition to, total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase (CAT), and enzymes activities were also assessed.

RESULTS

Colitis increased the levels of MDA and NO, and enhanced the inflammatory and apoptotic gene expressions, while reducing the SOD and CAT enzymes activity, and TAC levels in the colitis rats. Also, results showed that colitis was associated with the infiltration of inflammatory cells, epithelium damage, and edema in colon tissue. QA significantly ameliorated histopathological indices, oxidative stress, inflammation, and apoptosis in colitis rats.

CONCLUSION

QA ameliorated UC through the inhibition of two TLR4-NF-κB and NF-κB-INOS-NO signaling pathways, which results in the reduction of colitis complications, including oxidative stress, inflammation, apoptosis and histopathological injuries in rats. Therefore it can be concluded, that QA exerts its therapeutic effects through antiapoptotic, antioxidant, and anti-inflammatory properties.

New NADPH Oxidase 2 Inhibitors Display Potent Activity against Oxidative Stress by Targeting p22phox-p47phox Interactions

NADPH oxidase (NOX2) is responsible for reactive oxygen species (ROS) production in neutrophils and has been recognized as a key mediator in inflammatory and cardiovascular pathologies. Nevertheless, there is a lack of specific NOX2 pharmacological inhibitors. In medicinal chemistry, heterocyclic compounds are essential scaffolds for drug design, and among them, indole is a very versatile pharmacophore. We tested the hypothesis that indole heteroaryl-acrylonitrile derivatives may serve as NOX2 inhibitors by evaluating the capacity of 19 of these molecules to inhibit NOX2-derived ROS production in human neutrophils (HL-60 cells). Of these compounds, C6 and C14 exhibited concentration-dependent inhibition of NOX2 (IC₅₀~1 µM). These molecules also reduced NOX2-derived oxidative stress in cardiomyocytes and prevented cardiac damage induced by ischemia-reperfusion. Compound C6 significantly reduced the membrane translocation of p47^phox, a cytosolic subunit that is required for NOX2 activation. Molecular docking analyses of the binding modes of these molecules with p47^phox indicated that C6 and C14 interact with specific residues in the inner part of the groove of p47^phox, the binding cavity for p22^phox. This combination of methods showed that novel indole heteroaryl acrylonitriles represent interesting lead compounds for developing specific and potent NOX2 inhibitors.

Hydroxytyrosol and Arginine as Antioxidant, Anti-Inflammatory and Immunostimulant Dietary Supplements for COVID-19 and Long COVID

Phytochemicals from plant extracts are becoming increasingly popular in the world of food science and technology because they have positive effects on human health. In particular, several bioactive foods and dietary supplements are being investigated as potential treatments for chronic COVID. Hydroxytyrosol (HXT) is a natural antioxidant, found in olive oil, with antioxidant anti-inflammatory properties that has been consumed by humans for centuries without reported adverse effects. Its use was approved by the European Food Safety Authority as a protective agent for the cardiovascular system. Similarly, arginine is a natural amino acid with anti-inflammatory properties that can modulate the activity of immune cells, reducing the production of pro-inflammatory cytokines such as IL-6 and TNF-α. The properties of both substances may be particularly beneficial in the context of COVID-19 and long COVID, which are characterised by inflammation and oxidative stress. While l-arginine promotes the formation of ^•NO, HXT prevents oxidative stress and inflammation in infected cells. This combination could prevent the formation of harmful peroxynitrite, a potent pro-inflammatory substance implicated in pneumonia and COVID-19-associated organ dysfunction, as well as reduce inflammation, improve immune function, protect against free radical damage and prevent blood vessel injury. Further research is needed to fully understand the potential benefits of HXT and arginine in the context of COVID-19.

Myeloid-Derived Suppressor Cells in Cancer and COVID-19 as Associated with Oxidative Stress

Myeloid-derived suppressor cells MDSCs are a heterogeneous population of cells that expand beyond their physiological regulation during pathologies such as cancer, inflammation, bacterial, and viral infections. Their key feature is their remarkable ability to suppress T cell and natural killer NK cell responses. Certain risk factors for severe COVID-19 disease, such as obesity and diabetes, are associated with oxidative stress. The resulting inflammation and oxidative stress can negatively impact the host. Similarly, cancer cells exhibit a sustained increase in intrinsic ROS generation that maintains the oncogenic phenotype and drives tumor progression. By disrupting endoplasmic reticulum calcium channels, intracellular ROS accumulation can disrupt protein folding and ultimately lead to proteostasis failure. In cancer and COVID-19, MDSCs consist of the same two subtypes (PMN-MSDC and M-MDSC). While the main role of polymorphonuclear MDSCs is to dampen the response of T cells and NK killer cells, they also produce reactive oxygen species ROS and reactive nitrogen species RNS. We here review the origin of MDSCs, their expansion mechanisms, and their suppressive functions in the context of cancer and COVID-19 associated with the presence of superoxide anion •O2- and reactive oxygen species ROS.

Transcriptomic Analysis of Long Non-Coding RNA during Candida albicans Infection

Candida albicans is one of the most commonly found species in fungal infections. Due to its clinical importance, molecular aspects of the host immune defense against the fungus are of interest to biomedical sciences. Long non-coding RNAs (lncRNAs) have been investigated in different pathologies and gained widespread attention regarding their role as gene regulators. However, the biological processes in which most lncRNAs perform their function are still unclear. This study investigates the association between lncRNAs with host response to C. albicans using a public RNA-Seq dataset from lung samples of female C57BL/6J wild-type Mus musculus with induced C. albicans infection. The animals were exposed to the fungus for 24 h before sample collection. We selected lncRNAs and protein-coding genes related to the host immune response by combining the results from different computational approaches used for gene selection: differential expression gene analysis, co-expression genes network analysis, and machine learning-based gene selection. Using a guilt by association strategy, we inferred connections between 41 lncRNAs and 25 biological processes. Our results indicated that nine up-regulated lncRNAs were associated with biological processes derived from the response to wounding: 1200007C13Rik, 4833418N02Rik, Gm12840, Gm15832, Gm20186, Gm38037, Gm45774, Gm4610, Mir22hg, and Mirt1. Additionally, 29 lncRNAs were related to genes involved in immune response, while 22 lncRNAs were associated with processes related to reactive species production. These results support the participation of lncRNAs during C. albicans infection, and may contribute to new studies investigating lncRNA functions in the immune response.

Superoxide Anion Chemistry-Its Role at the Core of the Innate Immunity

Classically, superoxide anion O2•- and reactive oxygen species ROS play a dual role. At the physiological balance level, they are a by-product of O2 reduction, necessary for cell signalling, and at the pathological level they are considered harmful, as they can induce disease and apoptosis, necrosis, ferroptosis, pyroptosis and autophagic cell death. This revision focuses on understanding the main characteristics of the superoxide O2•-, its generation pathways, the biomolecules it oxidizes and how it may contribute to their modification and toxicity. The role of superoxide dismutase, the enzyme responsible for the removal of most of the superoxide produced in living organisms, is studied. At the same time, the toxicity induced by superoxide and derived radicals is beneficial in the oxidative death of microbial pathogens, which are subsequently engulfed by specialized immune cells, such as neutrophils or macrophages, during the activation of innate immunity. Ultimately, this review describes in some depth the chemistry related to O2•- and how it is harnessed by the innate immune system to produce lysis of microbial agents.